Risk factors for posttraumatic stress disorder following an industrial disaster in a residential area: A note on the origin of observed gender differences.

BACKGROUND Studies indicate that differences in trait anxiety and trauma-related distress may mediate the gender differences observed in posttraumatic stress disorder (PTSD). OBJECTIVE We examined the contributions of gender, trait anxiety, and trauma-related distress to the development of PTSD after an industrial disaster. METHODS Three months after a massive explosion in a fireworks factory in Kolding, Denmark, in November 2004, residents in the surrounding area were asked to complete the Harvard Trauma Questionnaire, the General Health Questionnaire, and a questionaire designed for the present study. Using multivariable logistic regression with PTSD as the dependent variable, we examined 4 explanatory models: (1) gender; (2) gender and trait anxiety; (3) gender, trait anxiety, and perceived danger; and (4) gender, trait anxiety, perceived danger, perceived hostility, feeling isolated, depersonalization, and behavioral self-blame. RESULTS Fifty-one percent (N = 516; 265 women and 251 men) of the area residents participated in the study. The female-to-male ratio of PTSD was 2.4:1. Women experienced significantly more trait anxiety (P < 0.001), feelings of isolation (P < 0.005), and behavioral self-blame (P = 0.018), and less perceived danger (P = 0.034) than did men. In multivariable logistic regression analysis, gender alone predicted 3.7% of the variance in PTSD status (odds ratio [OR] = 2.40; 95% CI, 1.35-4.27; P < 0.005); however, in all other models, gender was not significant. The final model comprised trait anxiety (OR = 1.20; 95% CI, 1.11-1.30; P < 0.001), perceived danger (OR = 4.62; 95% Cl, 2.24-9.50; P < 0.001), perceived hostility (OR = 5.21; 95% CI, 1.93-14.09; P < 0.001), feeling isolated (OR = 3.34; 95% CI, 1.55-7.16; P < 0.002), depersonalization (OR = 2.49; 95% CI, 1.42-4.37; P < 0.001), and behavioral self-blame (OR = 0.46; 95% CI, 0.24-0.86; P = 0.015), explaining 48.9% of the variance in PTSD severity. CONCLUSION This cross-sectional study found that gender was no longer associated with PTSD status when trait anxiety, perceived danger and hostility, feeling isolated, depersonalization, and behavioral self-blame were taken into account.